Electrostatic precipitators which use a plurality of electrodes to remove particulate matter must be cleaned periodically during operation if they are to function with any reasonable efficiency. Otherwise, the electrode will become coated with the matter which has been removed from the air or other gas circulating through the precipitator and will no longer attract the particulate matter with any reasonable degree of efficiency.
A common way to clean the electrodes is to provide rappers which are mechanically connected with one or more electrodes. While the precipitator is in operation, each rapper is periodically operated to vibrate an electrode or electrodes causing the accumulated particulate matter to drop off. Each rapper is conventionally composed of a solenoid coil encircling a core which strikes an anvil when the solenoid is energized. The anvil is mechanically connected with one or more electrodes which are vibrated when the anvil is struck by the core.
Rectified AC current is conventionally used as current to energize the rappers. In the past it has been necessary to provide at least two wires between each rapper and an electrical or electronic control which selectively distributes the current to the rappers to energize them. This results in the use of much wiring which adds considerably to the cost of constructing the precipitator and the expenditure of much labor in installing the wiring for the rappers in the precipitator. Consequently, the installation of the rappers is a somewhat difficult and costly construction step.